Sole for a shoe and related methods

ABSTRACT

A striking surface of a sole for a shoe comprises a central transition zone having a centerline extending substantially from the front of the sole to the rear of the sole, the central transition zone dividing the striking surface of the sole into a medial portion and a lateral portion. The medial portion of the striking surface is disposed at a first angle of inclination with respect to a support surface. The lateral portion of the striking surface is disposed at a second angle of inclination with respect to the support surface. The first angle of inclination may decrease along a length of the sole, from a front of the central transition zone to a rear of the central transition zone. The second angle of inclination may increase along a length of the sole, from a front of the central transition zone to a rear of the central transition zone.

INTRODUCTION

The present teachings relate to a sole for a shoe. In particular, the present teachings relate to a sole for a shoe that facilitates a more natural motion of the foot and thus enhances body performance.

BACKGROUND

The muscles of the leg and foot are designed to work best when moving on a naked foot. Warriors 3000 years ago wore flat-soled shoes. Indeed, up to the 15th century, shoes remained flat-soled, providing good balance and allowing the foot to work through its wide and opposed ranges of biomechanical movements. By the 16th century, some shoes had heels added to make people appear taller. However, up to the 1800's most shoes had flat soles, no cushioning, no arch support, no heels and no motion control support.

In 1844, Charles Goodyear fused rubber with canvas and leather. The first rubber-soled sport shoe was sold in 1850 and the first running spikes in 1852. In 1880 tennis shoes were produced as a flat rubber sole vulcanized to canvas. Reebok, formed in 1892, and given its current name in 1958, produced successful running spikes that were later copied and produced in Europe and the US. The predecessor to Adidas began marketing shoes in 1920 and, by the 1936 Olympic games, their shoes were regarded as the best sports shoes. After 1948, Adidas added heels to its shoes to compete against fashionable Keds® sneakers. Puma was spun off from Adidas in 1948 to continue making sports shoes rather than fashionable shoes.

Many running shoes today elevate a wearer's heels and include cushioning, motion control, and other design features that can hamper the natural biomechanics of the body including, for example, the biomechanics of the foot and leg. The trend toward higher heels, cushioning, and motion control has increased since the 1970s.

Recently, barefoot running (and footwear designed to mimic barefoot running) and running off of the mid foot or ball of the foot has gained popularity. Barefoot running has significant implications on biomechanics, because foot function has a vast effect on the body.

While certain orthopedic shoes available in the prior art may provide soles having limited areas of inclination to assist a person biomechanically, none of the shoes available or disclosed in the prior art encourage proper movement of the foot, simultaneously, along its three axes of movement.

A need exists for shoe designs, in particular for athletic shoe designs that do not impede natural biomechanics such that injuries can be reduced and performance can be enhanced.

SUMMARY

The vast majority of existing sport shoes can impede athletic performance at least by elevating the heel and restricting a foot's natural range of motion. In addition, barefoot running can result in a dysfunctional core if the foot has poor biomechanics. Thus, it would be desirable to provide a shoe that can accommodate poor foot biomechanics and at the same time allow the foot to move properly through its natural range of motions.

In accordance with various exemplary embodiments, the present teachings relate to the design of a sole for a shoe. The design can be applied to any shoe that is designed for weight bearing. The present teachings are directed towards optimizing the transfer of force through the entire width and length of the foot—thereby allowing for the body's natural movements and creating coiling efficiencies. This can result in many biomechanical advantages in the force coupling mechanism, throughout the body, and therefore can lead to an overall increase in power output.

In accordance with one aspect of the present teachings, a sole for a shoe having a front, a rear, a striking surface, a medial edge, and a lateral edge may be provided. The striking surface of the sole comprises a central transition zone having a centerline extending substantially from the front of the sole to the rear of the sole, a medial edge and a lateral edge, the central transition zone divides the striking surface of the sole into a medial portion and a lateral portion. The medial portion of the striking surface extends from a front of the central transition zone to a rear of the central transition zone, and a thickness of the sole decreases along a width of the medial portion from the medial edge of the central transition zone toward the medial edge of the sole. The lateral portion of the striking surface extends from the front of the central transition zone to the rear of the central transition zone, and a thickness of the sole decreases along a width of the lateral portion from the lateral edge of the central transition zone toward the lateral edge of the sole.

In accordance with another aspect of the present teachings, a sole for a shoe having a front, a rear, a striking surface, a medial edge, and a lateral edge may be provided. The striking surface of the sole comprises a central transition zone having a centerline extending substantially from the front of the sole to the rear of the sole, a medial edge, and a lateral edge. The central transition zone divides the striking surface of the sole into a medial portion and a lateral portion.

A front medial section of the striking surface has a width extending from the medial edge of the central transition zone to the medial edge of the sole. A thickness of the sole decreases along a width of the front medial section from the medial edge of the central transition zone toward the medial edge of the sole such that the front medial section is disposed at a first angle of inclination with respect to a support surface. A front lateral section of the striking surface has a width extending from the lateral edge of the central transition zone to the lateral edge of the sole. A thickness of the sole decreases along a width of the front lateral section from the lateral edge of the central transition zone toward the lateral edge of the sole such that the front lateral section is disposed at a second angle of inclination with respect to the support surface.

A rear medial section of the striking surface has a width extending from the medial edge of the central transition zone to the medial edge of the sole. A thickness of the sole decreases along a width of the rear medial section from the medial edge of the central transition zone toward the medial edge of the sole such that the rear medial section is disposed at a third angle of inclination with respect to the support surface. A rear lateral section of the striking surface has a width extending from the lateral edge of the central transition zone to the lateral edge of the sole. A thickness of the sole decreases along a width of the rear lateral section from the lateral edge of the central transition zone toward the lateral edge of the sole such that the rear lateral section is disposed at a fourth angle of inclination with respect to the support surface. The first angle of inclination may be greater than the second angle of inclination and the fourth angle of inclination may be greater than the third angle of inclination.

Rate of decrease of the thickness of the width (and hence the angle of inclination) for medial and lateral portion is envisaged to change gradually from the front to the rear of the central transition zone and the length of the shoe sole. Gradual change in the angles of inclination is envisaged along the medial portion from the front portion that has a first angle of inclination to the rear portion that has a third angle of inclination. Similar gradual change is envisaged for the lateral portion.

A front portion of the sole may have a thickness greater than a thickness of a rear portion of the sole, such that a thickness measured at a front of the centerline of the central transition zone of the sole is greater than a thickness measured at a rear of the centerline of the central transition zone of the sole.

In accordance with another aspect of the present teachings, a method for utilizing a shoe sole to coordinate simultaneous movement of a foot along a sagittal axis, a frontal axis, and a transverse axis may be provided. The method comprises maintaining the foot in a natural supinated position when a striking surface of the sole strikes a surface being traversed, and transitioning the foot over a central transition zone of the sole to roll inwardly into a push-off pronated position. Transitioning the foot includes moving the striking surface of the sole from a rear lateral portion of the striking surface that forms a lateral angle of inclination with a support surface to a front medial portion of the striking surface that forms a medial angle of inclination with the support surface.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present teachings, as claimed.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the present teachings and, together with the description, serve to explain the principles of the present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom perspective view of a right shoe having a sole in accordance with an exemplary embodiment of the present teachings.

FIG. 2 is a front view of a right shoe including a sole in accordance with an exemplary embodiment of the present teachings.

FIG. 3 is a rear view of a right shoe including a sole in accordance with an exemplary embodiment of the present teachings.

FIG. 4 is a lateral side view of a right shoe including a sole in accordance with an exemplary embodiment of the present teachings.

FIG. 5 is a medial side view of a right shoe including a sole in accordance with an exemplary embodiment of the present teachings.

FIG. 6 is a bottom view of an exemplary right shoe sole in accordance with the present teachings, such as the exemplary embodiment shown in FIGS. 1-5.

FIG. 7 illustrates a foot in supination.

FIG. 8 illustrates a foot in pronation.

FIG. 9 is a top view of a right shoe having a sole in accordance with an exemplary embodiment of the present teachings.

FIGS. 10A-10H are cross-sectional views taken across the width of the shoe sole of FIG. 9 showing a variable width thickness (or variable angles of inclination) along a length of the shoe sole in accordance with an exemplary embodiment of the present teachings.

FIGS. 11A-11C are longitudinal cross-sectional views taken along the length of the shoe sole of FIG. 9 showing one possible variation in a central transition zone configuration in FIG. 11B along a length of the shoe sole in accordance with an exemplary embodiment of the present teachings.

FIG. 12 is a bottom view of a right shoe having a sole in accordance with an exemplary embodiment of the present teachings.

FIGS. 13A-13D illustrate exemplary embodiments of a cross-section of a sole with particular focus on the central transition zone (in the circle area) of the shoe sole of FIG. 12 in accordance with exemplary embodiments of the present teachings.

FIGS. 14A-14C are longitudinal cross-sectional views taken along the length of the shoe sole of FIG. 12 in accordance with exemplary embodiments of the present teachings.

FIGS. 15A-15D are enlarged cross-sectional views of a central transition zone of the shoe sole of FIGS. 13A-13D, respectively, in accordance with exemplary embodiments of the present teachings.

FIGS. 16A-16D illustrate exemplary embodiments of a cross-sectional perspective view of a sole with particular focus on the central transition zone of the shoe sole of FIG. 12 in accordance with exemplary embodiments of the present teachings.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of the present teachings, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Anatomic terms for location of body parts and motions are helpful for a variety of reasons. In the context of describing motion of a foot herein, for example, “medial” means toward the center line of the body, “lateral” means away from the center line of the body, “distal” means further from the body, “proximal” means closer to the body, “anterior” means the front of the body, “posterior” means the back of the body, “dorsal” means the top of the foot, and “plantar” means the bottom of the foot.

Considering a typical human foot, the big toe is medial and the little toe is lateral. The toes are distal to the midfoot and the midfoot is distal to the heel bone. The heel bone is proximal to the toes. The toes are also considered anterior to the midfoot and the heel is posterior to the midfoot. As used herein, when describing a shoe sole according to the present teachings, the term “inner” is used interchangeably with the term “medial” to refer to an area that would correspond to an inner or medial portion of the foot, i.e., the portion of the foot toward the centreline of the body. Similarly, as used herein, when describing a shoe sole according to the present teachings, the term “outer” is used interchangeably with the term “lateral” to refer to an area that would correspond to an outer or lateral portion of the foot.

Many conventional athletic shoes hinder the proper and natural motion of the foot during, for example, walking, running, and jumping. For proper motion, the foot must be able to move, simultaneously, along three axes. Movement along the three axes can be analogized to movement of an airplane for ease of understanding: (1) movement of the foot about its sagittal axis allows the airplane to tip its nose (toes) up or down while the tail of the airplane (heel) moves in the opposite direction; (2) movement of the foot about its frontal axis allows the airplane to rock the left wing (medial side, inside of the foot) upward or downward while the right wing (lateral side, outside of the foot) moves in the opposite direction, and vice versa; (3) movement of the foot about its transverse axis allows one side of the airplane to yaw to the right or left sides (medially or laterally) while the other side yaws in the opposite direction. The transverse axis can be considered to extend along or parallel to the shin and through the ankle so that the foot rotates somewhat about the ankle.

Regarding movement of the foot, dorsiflexion is pivoting of the foot about its sagittal axis, allowing the toes to move upward and the heel to move downward. Plantarflexion is pivoting of the foot about its sagittal axis, allowing the toes to move downward and the heel to move upward. Abduction is movement of the front of the foot about its transverse axis, allowing the front of the foot to yaw outwardly or laterally while the heel moves in the opposite direction (medially). Adduction is movement of the front of the foot about its transverse axis, allowing the front of the foot to yaw inwardly or medially while the heel moves in the opposite direction (laterally). Inversion is movement of the foot about its frontal axis, allowing the foot to rock the medial side (inside) of the foot upward so that the planter surface faces outward and upward while the lateral side (outside) of the foot moves downward. Eversion is movement of the foot about its frontal axis, allowing the foot to rock the lateral side (outside) of the foot upward and outward while the medial side (inside) of the foot moves downward.

Supination and pronation are a combination of the above motions. It is common to use supination and inversion interchangeably and pronation and eversion interchangeably; however, supination is actually a combination of inversion, plantarflexion and adduction. Pronation is a combination of eversion, dorsiflexion and abduction. Supination and pronation are illustrated, respectively, in FIGS. 7 and 8.

In supination, the heel rotates away from the center of the body, the big toe moves away from the center of the body, the foot flexes down and the ankle rolls out. In pronation, the heel rotates towards the center of the body, the little toe moves upward and towards the center of the body, the foot flexes up slightly and the ankle rolls in. If a person stands with their feet parallel and facing forward and rotates their body to look over their left shoulder without moving their feet, the left leg rotates out (i.e., an external leg rotation) and their weight is on the outside of the left foot—thus their left foot is supinated. The right leg has rotated in (i.e., an internal leg rotation) and their weight is on the inside of the right foot—thus their right foot is pronated.

In order for the foot to work correctly, it needs to have the ability to move simultaneously through all three axes of movement. Providing a flat-bottomed sole on a typical athletic shoe, especially where the heel is higher than the forefoot, will not allow normal functional biomechanics of the foot (e.g., movement along all three axes) to occur as this is a one dimensional design while a three dimensional design is required.

During walking, running, jumping and similar movements, in normal biomechanics, the human foot moves from natural supination to a natural pronation (avoiding over pronation), and a shoe sole in accordance with the present teachings allows this to occur in a natural manner by allowing the energy to move from the outside back area of the foot, forward in a curved manner to the inside front area. Embodiments of a shoe sole in accordance with the present teachings allow simultaneous movement through all three axes and allow the wearer to move away from heel strike to proper forefoot movement, e.g., when walking, running, jumping, etc. at their rate of adaptation.

The design of a shoe sole in accordance with various exemplary embodiments of the present teachings takes into account that humans tend to mainly walk on flat surfaces in modern environments. While surface gradients may change, surfaces typically remain substantially flat. Embodiments of a shoe sole in accordance with the present teachings can provide horizontally-opposed sections on a bottom surface of the shoe sole, giving the bottom profile of the sole (i.e., the portion of the shoe sole that contacts the surface that the wearer is traversing) a non-flat shape or contour so that, as the foot contacts a typical flat surface, the sole does not present a flat surface to the wearer's foot. Embodiments of a shoe sole in accordance with the present teachings can additionally provide a sole that is higher (e.g., thicker) in the front than at the rear, encouraging the wearer of the sole to move from a heel-strike stride to mid-foot or ball-of-foot strike at a pace that will not overload the musculoskeletal system. In the natural motion of walking, running, jumping, and similar motion, there is an appropriate time for the heel to strike the floor—when a person is slowing down.

A shoe sole in accordance with various exemplary embodiments of the present teachings is configured to encourage people to run on their forefoot, rather than heel striking, and also to appropriately roll from the lateral part (outside) of their foot to the medial part (inside) of their foot in a controlled manner during walking, running, and similar movement, for normal pronation and avoid over pronation.

A shoe sole in accordance with various exemplary embodiments of the present teachings can include one or more of the following attributes: (1) the sole is higher (e.g., thicker) in the front than in the back; (2) the bottom of the sole (which contacts the surface being traversed) is not flat; and (3) a surface contour of the bottom of the sole progressively changes, with the contour of the sole varying from a greater lateral angle bias in the rear portion of the sole to a greater medial angle bias in the front portion of the sole relative to the floor. This enables the transfer from a naturally supinated foot position to a naturally pronated foot position (via simultaneous movement through all three axes mentioned before). Furthermore, such movement promotes pushing off from the medial ball of the foot and the pad of the great toe. The sole being higher in the front can encourage running off the forefoot. Being non-flat on the bottom and having a varying surface contour with a central transition zone can encourage normal pronation while also providing a suitably stable and protective surface for the foot as this movement lock the joints of the foot for preparation of the pushing off the earth phase of movement.

The central transition zone marks a point of transition on the sole from a medial portion of the sole to a lateral portion of the sole. The central transition zone is generally centrally located between the medial and lateral edges of the sole, extends in length between the front and the rear of the shoe for at least a portion of the length of the shoe, generally follows the curve of the medial edge of the sole, and has a width such that it includes a centerline, a lateral edge, and a medial edge. A width of the medial portion extends between the medial edge of the central transition zone and the medial edge of the sole and a width of the lateral portion extends between the lateral edge of the central transition zone and the lateral edge of the sole. A thickness of the medial portion of the sole tapers or decreases along its width from the medial edge of the central transition zone toward the medial edge of the sole. A thickness of the lateral portion of the sole tapers or decreases along its width from the lateral edge of the central transition zone toward the lateral edge of the sole.

The change in thickness of the sole in the cross-section of each of the medial portion and the lateral portion may be greater in one of the medial and lateral portions than in the other of the medial and lateral portions. Alternatively, the change in thickness in the cross-section of the sole in each of the medial and lateral portions may be the same.

Additionally or alternatively, the change in thickness within a medial portion, a lateral portion, or within both portions may vary along a length of the respective portion. Such a variation in thickness may be progressive along a length of the respective portion, i.e., the thickness may progressively increase or decrease, for example by steps or degrees. The variation in thickness also may be continuous along a length of the respective portion, i.e., the thickness may continuously increase or decrease.

Additionally or alternatively, the width of the medial portion of the sole forms a first angle of inclination with respect to the ground/floor/surface upon which the sole rests. The angle of inclination of the medial portion is measured medially from the medial edge of central transition zone and may be about 0 degrees to about 15 degrees. The width of the lateral portion of the sole forms a second angle of inclination with respect to the ground/floor/surface upon which the sole rests. The angle of inclination of the lateral portion is measured laterally from the lateral edge of central transition zone and may be about 0 degrees to about 15 degrees.

The angle of inclination for one of the medial and lateral portions may be greater than the angle of inclination for the other of the medial and lateral portions. Alternatively, the angle of inclination for each of the medial and lateral portions may be the same. Additionally or alternatively, the angle of inclination within a medial portion, a lateral portion, or within both portions may vary along a length of a respective portion. Such a variation in inclination may be progressive along a length of a respective portion, i.e., the angle of inclination may progressively increase or decrease from a front to a rear of the sole, for example by steps or degrees. The variation in angle of inclination also may be continuous along a length of the respective portion, i.e., the angle of inclination may continuously increase or decrease. The angle of inclination may increase along a length of one portion (medial for example) while decreasing along a length of the other portion (lateral for example).

The contour of sole can include medial and lateral portions that extend through the full length of the sole. The size, orientation, angle of inclination, and thickness of a portion at any point along a length of a sole can vary dependent upon the wearer, the intended use, and the size of the sole or along a part thereof. Alternatively, the design of medial and lateral portions may encompass only a portion of the sole.

A thickness of the sole along its length (from the front to the rear of the sole) and measured along the centerline of the central transition zone, may be uniform or it may vary. The thickness of the sole may decrease from a front of the sole to a rear of the sole. Such a variation in thickness may be progressive and/or continuous. The variation in thickness of the sole along its length can vary depending on the wearer, the intended use, and the size of the sole. Alternatively, it is possible that the thickness of the sole along its length (from the front to the rear of the sole) and measured along the centerline of the central transition zone may vary such that the thickness of the sole is greater at the rear of the sole than at the front of the sole.

Size, shape, length, thicknesses and angles being dependent on the wearer can mean, for example, dependence on one or more of a wearer's level of skill, biomechanics, goals, shoe width, particular sport and personal preferences.

FIG. 1 is a bottom perspective view of a shoe 100 having an upper 180 and a sole 110 in accordance with an exemplary embodiment of the present teachings. The bottom surface of the sole 110 can be referred to as the “striking surface,” because it strikes the ground in operational use of the shoe sole. The sole 110 includes a front 170 and a rear 175, perhaps best shown in the views of FIGS. 3-5.

With reference also to FIG. 6, sole 110 includes a central transition zone 120 having centerline L, a medial edge e_(i), and a lateral edge e_(o). A width e of the central transition zone 120 is defined between the medial edge e_(i) and the lateral edge e_(o). The width e (see FIGS. 3, 6, 13A-13D, 15A-15D, and 16A-16D) of the central transition zone 120 can depend on shoe size, the wearer, and the intended use. The width e can range, for example, from about 0.5 mm to about 20 mm, as measured from the medial edge e_(i) of the central transition zone 120 to the lateral edge e_(o) of the central transition zone 120. The width of the central transition zone may vary along a length of the central transition zone. The location, width, length, and profile of the central transition zone can vary depending on the wearer, the intended use, and the size of the sole.

The central transition zone 120 can run from the front 170 of the sole to the rear 175 of the sole and preferably has a curvature as shown in FIG. 6 which is similar to the medial curve of the sole 110. Embodiments of the present teachings contemplate the central transition zone 120 running the entire distance from the front of the sole to the rear of the sole, but in preferred embodiments the central transition zone extends along at least 20% of the length B of the sole.

In various exemplary embodiments, and as illustrated in FIG. 15 D, the central transition zone 120 is substantially flat to promote stability of the sole 110. However, the present teachings contemplate a central transition zone 120 that is not completely flat. For example, as illustrated in FIGS. 13A-13C, 15A-15C, and 16A-16C, the central transition zone 120 may be rounded, presenting a convex surface profile, pointed or having a triangular profile, or may comprise an indented gap along its length, or the profile may include a combination of these shapes. The profile may vary along a length of the central transition zone 120.

As illustrated in FIGS. 1 and 6, the central transition zone 120 divides the striking surface 110 into a medial portion 123 and a lateral portion 127. The medial portion 123 extends from a front of the central transition zone 120 to a rear of the central transition zone 120, and a thickness of the sole decreases along a width of the medial portion from the medial edge e_(i) of the central transition zone toward the medial edge of the sole 110. The lateral portion 127 extends from the front of the central transition zone 120 to the rear of the central transition zone 120, and a thickness of the sole decreases along a width of the lateral portion 127 from the lateral edge e_(o) of the central transition zone 120 toward the lateral edge of the sole 110. The medial and lateral portions 123, 127 may extend along an entire length of the sole, from the front to the rear of the sole. Alternatively, the medial and lateral portions may extend along only a portion of the length of the sole 110.

A rate of decrease in thickness of the width of each of the medial and lateral portions 123, 127 from the central transition zone 120 to the respective medial and lateral edges of the sole 110 may remain constant for an entire length of each of the lateral and medial portions, or the rate of decrease in thickness may increase or decrease along the length of either of the medial and lateral portions. Further, the rate of decrease may vary progressively and/or continuously.

Additionally or alternatively, the medial portion 123, from the medial edge e_(i) of the central transition zone to the medial edge of the sole, is disposed at a first angle of inclination with respect to a support surface upon which the sole rests or strikes. The lateral portion 127, from the lateral edge e_(o) of the central transition zone to the lateral edge of the sole, is disposed at a second angle of inclination with respect to the support surface. The incline of each of the lateral and medial portions 123, 127, with respect to the support surface, may be about 0° to about 15.0° including any decimal variations.

In certain embodiments of the present teachings, the medial portion 123 includes a front medial section 130 and a rear medial section 160 of the sole 110. Similarly, the lateral portion 127 includes a front lateral section 140 and a rear lateral section 150. A convergence zone or line 125 (see FIGS. 1 and 6) represents an area of transition between the front and rear portions of the sole 110 as well as the lateral and medial portions of the sole 110. The convergence zone or line 125 designates an area of the sole which facilitates a transfer of foot movement from the rear lateral section 150 of the sole 110 to the front medial section 130 of the sole 110. There is little to no difference between angles of inclination for the front medial, front lateral, rear medial, and rear lateral sections of the sole 110 at the convergence zone 125, which promotes stability in the sole and facilitates movement from the rear lateral section of the sole to the front medial portion of the sole.

In various exemplary embodiments of the present teachings, the very front of the front lateral section 130 of the sole 110 (an area that corresponds to the big toe area of a wearer) has a first thickness that decreases from the medial edge e_(i) of the central transition zone 120 to the medial edge of the front of the sole 110. The very front of the front lateral section 140 of the sole 110 (an area that corresponds to the small toe area of a wearer) has a second thickness that decreases from the lateral edge e_(o) of the central transition zone 120 to the lateral edge of the front of the sole 110. The surface at the front of the medial front section 130 of sole 110 has a greater incline from the central transition zone relative to the striking ground than the surface at the front of the lateral front section 140, as can be seen in FIG. 2, which illustrates a front view of the sole 110 attached to an upper 180. The very rear of the rear medial section 160 of the sole 110 (an area that corresponds to the medial heal area of a wearer) has a third thickness that decreases from the from the medial edge e_(i) of the central transition zone 120 to the medial edge of the rear of the sole 110. The very rear of the rear lateral section 150 of the sole 110 (an area that corresponds to the lateral heal area of a wearer) has a fourth thickness that decreases from the lateral edge e_(o) of the central transition zone 120 to the lateral edge of the rear of the sole 110. The surface at the back of the lateral rear section 150 of sole 110 has a greater incline from the central transition zone 120 relative to the striking ground than the surface of the back of the medial rear section 160 of sole 110, as can be seen in FIG. 3, which illustrates a rear view of the sole 110 attached to the upper 180.

The decrease in thickness across each of the front medial section 130, the front lateral section 140, the rear medial section 160, and the rear lateral section 150 may be progressive decreases in thickness. Additionally, the decreases in thickness may be continuous decreases from the central transition zone 120 to the respective edge of the sole 110. The thickness of the sole in any of the medial and lateral, front and back sections need not be constant. Rather, the present teachings contemplate that the thickness of the sole 110 progressively changes along the length of an entire medial and/or lateral portion, and hence both front and rear portions as shown in FIGS. 9 and 10A-10H. As shown in FIGS. 9 and 10A-10H, the contour of the surface of the sole may continuously or progressively change along the length of the sole, such that an angle of inclination of a portion of the sole, such as a medial or lateral portion of the sole, changes throughout the length of the sole. As used herein, the term “contour” is used to refer to the angle of inclination of the surface of the sole with respect to a support surface. For example, a portion of the sole having a first angle of inclination (or contour) may have a width that presents a curved appearance or a straight (or flat) appearance. For example, as illustrated in FIG. 3, a width of the medial portion, identified as D₄ has a gently curved appearance. The curvature is for aesthetic purposes only and does not impact the angle selection. Similarly, the width of the lateral portion, identified in FIG. 3 as D₃, has a more straight, or flat, or not curved appearance when contrasted with D₄. Again, this is for aesthetic purposes only and does not impact the angle selection. Either portion could be curved or straight.

Stated another way, although the sole 110 may be defined as having four sections (front medial, front lateral, rear lateral, and rear medial), it need not be so limited. For example, as shown in FIGS. 9 and 10A-10H, an angle of inclination of the medial portion 123 of the sole 110 or the lateral portion 127 of the sole 110 may vary along a length of the entire sole 110. In accordance with various embodiments, the variations in angles of inclination of the surface of sole 110 relative to the horizontal surface on which the sole rests can be, for example, from about 0° to about 15.0° including any decimal variations. The present teachings contemplate that the incline of the surfaces of sole 110 can vary and be selected as desired, for example based on the shoe size, the wearer, and the intended activity.

Alternatively, only a front portion or a rear portion of the sole may form an angle of inclination with respect to a support surface. For example, the surfaces of the front medial and front lateral sections 130, 140 of sole 110 can form angles of inclination of between about 0° to about 15.0°, including any decimal variations, with the support surface while the surfaces of rear lateral and rear medial sections 150, 160 remain flat relative to the support surface. Similarly, the surfaces of the front medial and front lateral sections 130, 140 of sole 110 can remain flat relative to the support surface while the surfaces of rear lateral and rear medial sections 150, 160 form angles of inclination of between about 0° to about 15.0°, including any decimal variations, with the support surface. It is further contemplated that only one section of the sole may form an angle of inclination with the support surface or only one section of the sole may remain flat relative to the support surface.

In an exemplary embodiment of the present teachings, a surface of sole 110 at the very front of the medial front portion 130 has an angle of inclination of about 8°, a surface of sole 110 at the very front of the lateral front portion 140 has an angle of inclination of about 3°, a surface of sole 110 at the very back of the lateral rear portion 150 has an angle of inclination of about 7°, and a surface of sole 110 at the very back of the medial rear portion 160 has an angle of inclination of about 2°.

In one embodiment of the present teachings, the angle of inclination of the sole 110 with respect to the support surface gradually changes from the very front of the medial front section 130 to the very rear of the medial rear section 160 to provide a smooth transition between the different inclinations of the medial portion 123 of sole 110. See, for example, FIGS. 9 and 10A-10H. Hence in this example, along the length of the medial portion 123, angles of inclination progressively increase from about 2° at the very rear of the medial portion 123 to about 8° at the very front of the medial portion 123. In addition, the angle of inclination the sole 110 gradually changes from the very front of the lateral front section 140 to the very rear of the lateral rear section 150 to provide a smooth transition between the different inclinations of the lateral portion 127 of sole 110. Hence in this example, along the length of the lateral portion 127, angles of inclination progressively decrease from about 7° at the very rear of the lateral portion 127 to about 3° at the very front of the lateral portion 127.

The convergence zone 125, perhaps best shown in FIG. 6 as a horizontal dashed line illustrates an area in which front sections (130 and 140) and rear sections (150 and 160) meet. In accordance with the embodiment shown in FIG. 6, including exemplary relative dimensions, the front medial and front lateral sections 130, 140 of the sole 110 can extend from about 20% to about 80% of the length B of the shoe sole, hence defining the convergence zone 125. Similarly, the rear medial and rear lateral portions 150, 160 of the sole 110 can extend from about 20% to about 80% of the length B of the sole. Referring again to FIG. 2, which provides a front view of a shoe 100 including a sole 110 in accordance with an exemplary embodiment of the present teachings, the upper 180 is generally depicted as a conventional laced shoe, though those skilled in the art will appreciate that a sole in accordance with the present teachings can be utilized with a variety of shoe types including, but not limited to, sneakers, mules, sandals, flip flops, platform shoes, moccasins, espadrilles, saddle shoes, slip-on shoes, boat shoes, boots, slippers, minimalist shoes such as Vibram®FiveFingers® shoes, running shoes, track spikes, cleats, golf shoes, bowling shoes, climbing shoes, hiking shoes, and walking shoes.

In certain embodiments of the present teachings, the central transition zone 120 can include a peak 200 at a front of the sole having a height H₁ as measured from where the sole 110 attaches to the upper. In the front view provided in FIG. 2, on the lateral side of the central transition zone 120 is the very front of the lateral portion 127 and its front section 140, having an incline β of, for example, about 3°. On the medial side of the central transition zone 120 is the very front of the medial portion 123 and its front section 130 having an incline a of, for example, about 8°. The width D₂ of the lateral front section 140 can vary with the sole (i.e., shoe) size and can range, for example, from about 40% to about 80% (including all decimal variations) of the width of the sole, with width of the shoe sole at this point of intersection being defined as D₁₊D₂. The width D₂ is defined by D₁, as per above where D₁+D₂ will equal the width of the sole at this particular intersection point.

With reference to FIG. 3, which provides a rear view of a shoe 100 including a sole 110 in accordance with an exemplary embodiment of the present teachings, the rear portion of sole 110 includes the central transition zone 120. In certain embodiments of the present teachings, the central transition zone 120 can include a peak 300 at a rear 175 of the sole 110 having a height H₂, as measured from where the sole 110 attaches to the upper. On the lateral side of the central transition zone 120 is the very back of the lateral portion 127 and its rear section 150 having an incline δ of, for example, about 7°. On the medial side of the central transition zone 120 is the very back of the medial portion 123 and its rear section 160 having an angle of inclination γ of, for example, about 2°. The width D₃ of the lateral rear section 150 can vary with shoe size and can range from about 40% to about 80% (including all decimal variations) of the width of the shoe, with width of the shoe at this point of intersection being defined as D₃₊D₄. The width D₄ of the medial rear section 160 is defined by D₃ as per above where D₃₊D₄ equals the rear width of the sole at this particular intersection point.

A sole 110 having surfaces that form angles of inclination with respect to a support surface, particularly when the angles of inclination vary progressively along a length of the sole 110, as described above, encourages proper movement of the foot during a variety of activities, simultaneously, along three axes—the sagittal axis, frontal axis, and the transverse axis. As the sole 110 strikes the surface being traversed, it encourages the foot to maintain its natural supinated position due to the angle of inclination of the surface of outer rear portion 150 of sole 110. The foot then transitions over the central transition zone 120 to roll medially into pronation due to the angle of inclination of the surface of front medial section 130 of sole 110, as the heel rises off the floor thereby preventing over pronation and locking up the foot for preparation of the push off phase of movement, locking up the foot joints.

FIG. 4 is a lateral side view of a shoe 100 including a sole 110 in accordance with the present teachings. In the illustrated exemplary embodiment, the sole 110 is attached to an upper as described above with respect to FIG. 2. As shown, the sole 110, along its centerline L has a height H₁ at its front 170 that is greater than a height H₂ at its rear 175. As illustrated, the width of the sole 110 decreases on the lateral edge (a width of the lateral edge of sole 110 being defined between an upper surface of sole 110 and lower lateral edge 177 of sole 110), relative to the width on the centerline L of central transition zone 120, causing changes in the height of the sole along the lateral edge. The height of the sole on its lateral edge changes from front to the back, as can be seen in FIG. 4. In an exemplary embodiment, the height H₁ at the front 170 of the sole 110 can be, for example, about 12 mm. The height H₂ at the rear 175 of the sole 110 can be, for example, about 5 mm. The thickness of the sole 110 and the relative heights H₁ and H₂ can vary depending on, for example, the size of the shoe, the wearer, the amount of cushioning desired, the composition of the sole, and the intended use of the shoe. The height H₁ at the front 170 of the sole 110 can be, for example, at least twice the height H₂ at the rear 175 of the sole 110. Embodiments of the present teachings having a height H₁ at the sole front 170 that is greater than a height H₂ at the sole rear 175 can encourage wearers to properly run on their forefoot at their adaptive rate, rather than heel striking. H₁ can range from about 5 mm to about 30 mm and any decimal variations thereof. H₂ can range from about 1 mm to about 20 mm. H₁ may be greater than or equal to H₂. Alternatively, H₂ may be greater than H₁.

FIG. 5 is a medial side view of a shoe 100 including a sole 110 in accordance with the present teachings. In the illustrated exemplary embodiment, the sole 110 is attached to the upper 180 as described above with respect to FIGS. 2 and 3. As shown, the sole 110, along centerline L of central transition zone 120, has a height H₁ at its front 170 that is greater than a height H₂ at its rear 175. As described above and illustrated in FIG. 5, the width of the sole decreases on the medial edge (a width of the medial edge of sole 110 being defined between an upper surface of sole 110 and lower medial edge 179 of sole 110), relative to the width at the centerline L, causing changes in the height of the sole 110 along the medial edge. The height of the sole 110 on its medial edge changes from front to the back, as can be seen in FIG. 5. In an exemplary embodiment, the height H₁ at the front 170 of the sole 100 can be, for example, about 12 mm. The height H₂ at the rear 175 of the sole can be, for example, about 5 mm. The thickness of the sole 110 and the relative heights H₁ and H₂ can vary depending on, for example, the size of the shoe, the wearer, the amount of cushioning desired, the composition of the sole, and the intended use of the shoe. Embodiments of the present teachings having a height H₁ at the sole front 170 that is greater than a height H₂ at the sole rear 175 can encourage wearers to properly run on their forefoot rather than heel striking. H₁ may be greater than or equal to H₂. Alternatively, H₂ may be greater than H₁.

FIG. 6 is a bottom view of a shoe sole 110 in accordance with the present teachings, such as the sole embodiment shown in FIGS. 1-5, exemplary dimensions of which are labeled. The shoe sole has a length B that varies with shoe size. In the illustration, the centerline L of the central transition zone 120 of the sole 110 is spaced a distance a₁ from a line designating an inside boundary of the maximum width A. In certain embodiments of the present teachings, distance a₁ can be, for example, between about 40% and about 80% of the width A of the sole. A distance a₂ from the centerline L of the sole 110 to an adjacent medial edge of the sole 110 can be, for example, between about 40% and about 80% of the width A of the sole.

As stated above, the medial front section 130 and the lateral front section 140 of the sole 110 can extend, for example, over about 60% of the shoe sole length B. This distance is shown as distance b in FIG. 6. The location at which the medial front section 130 and lateral front section 140 of the sole 110 end and the lateral rear section 150 and medial rear section 160 of the sole 110 begin can be referred to as the convergence zone 125. As stated above, the convergence zone 125 need not provide a drastic change of inclination because the transition in the incline from the front to the rear of both the medial and lateral portions 123, 127 is preferably gradual and progressive. Angles of inclination for the medial and lateral portions can be, but need not be, the same at any point along the convergence zone 125. The present teachings contemplate that the convergence area 125 can facilitate a smooth transition between the front and rear portions of the sole. Embodiments of the present teachings contemplate the distance b varying from about 20% of the shoe sole length B to about 80% of the shoe sole length B.

As one of ordinary skill in the art will appreciate, utilizing the variable contour design of the sole with various combinations of the shape, size, and position of the central transition zone will allow for customization of the sole characteristics for different types of wearers. Similarly, varying angles of inclination of various sections of the medial and lateral portions 123, 127 of the sole 110 will allow further customization. For example, various sections of the sole 110 may present angled surfaces of flat surfaces relative to the support surface such that only a front portion or a rear portion of the sole may form an angle of inclination with respect to a support surface. Alternatively only one section of the sole may form an angle of inclination with the support surface or only one section of the sole may remain flat relative to the support surface.

A sole having variable contour design, according to the present teachings, facilitates natural movement of the wearer's foot along its three axes of movement simultaneously. The angles of the different portions of the sole can affect the speed of the foot as it moves from a lateral rear position to a medial front position. For example, a larger difference between the angles of the lateral and medial sides of the sole will promote faster movement of the foot from the lateral to medial position as the foot moves along its three axes. As one of ordinary skill in the art would understand, when combined with a central transition zone having a shape and/or position as described herein, the sole can be further customized for particular types of sports or to address characteristics of the wearer. For example, the central transition zone can be positioned to provide a larger or smaller lateral striking surface. Similarly, the shape of the central transition zone can be used to affect speed of movement of the foot as it moves from the lateral to the medial side, with a triangular shape, for example, aiding in pivoting of the foot and, thus, increasing the speed of the movement of the foot from the lateral to medial position. Such a configuration could be further enhanced by providing gaps in the triangular-shaped central transition zone, which also aid in pivoting of the foot on the striking surface. Faster movement of the foot from the lateral to medial position permits a wearer to generate more power as they push off the ground harder and faster (Newton's 2^(nd) Law). Wearers that participate in activities such as road running, sprinting, golf, tennis, football, badminton, basketball, and baseball to name a few, may benefit from a shoe sole that promotes speed of transfer from the lateral to medial position of the foot.

Similarly, as noted above, the central transition zone can affect the lateral to medial bias of the portions of the sole and can be positioned to eliminate undesirable biomechanics of the user. It could be utilized to provide a greater area of contact between the ground and the medial or lateral surfaces depending on what is more desirable. For example, while it is desirable that the foot moves into the natural position of pronation, over pronation is undesirable and can be eliminated through use of variations in a contour of the sole in combination with selection of a larger lateral rear foot portion angle bias to keep the user in a natural supinated position for a longer period within the gait cycle eliminating the possibility of excessive pronation. Similarly, a system having front portions that present angles of inclination relative to the support surface can have a transition zone allowing for a greater area of contact with the ground between the lateral side than the medial side (i.e. front lateral width D1 is around 80 percent of the width D1+D2) encouraging the wearer to maintain a longer contact time on the lateral side and hence eliminating over pronation.

In another application, the variable contour design may be selected to promote forefoot strike as opposed to heel strike. In addition to the benefits outlined above, a wearer that utilizes a sole that facilitates a forefoot strike also may see the benefit of activation of the gluteal muscles along with the integration of the abdominal musculature.

In accordance with the various embodiments, one of ordinary skill in the art will appreciate that a sole according to the present teachings may be made using conventional materials and molding techniques.

In accordance with various embodiments of the present teachings, the exact ratios and characteristics can depend on the individual and the intended use of the shoe. As one of ordinary skill in the art will appreciate, the present teachings may be used in any combination to create shoe soles having characteristics tailored to an individual wearer or an intended use of the shoe or both.

Other embodiments of the present teachings will be apparent to those skilled in the art from consideration of the specification and practice of the present teachings disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the present teachings being indicated by the following claims. 

What is claimed is:
 1. A sole for a shoe having a front, a rear, a striking surface, a medial edge, and a lateral edge, the striking surface of the sole comprising: a central transition zone having a centerline extending substantially from the front of the sole to the rear of the sole, a medial edge and a lateral edge, the central transition zone dividing the striking surface of the sole into a medial portion and a lateral portion; the medial portion of the striking surface extending from a front of the central transition zone to a rear of the central transition zone, a thickness of the sole decreasing along a width of the medial portion from the medial edge of the central transition zone toward the medial edge of the sole; and the lateral portion of the striking surface extending from the front of the central transition zone to the rear of the central transition zone, a thickness of the sole decreasing along a width of the lateral portion from the lateral edge of the central transition zone toward the lateral edge of the sole.
 2. The sole of claim 1, further comprising a frontal portion of the sole, wherein a decrease in the thickness of the sole along the width of the lateral portion in the frontal portion of the sole is less than a decrease in the thickness of the sole along the width of the medial portion in the frontal portion of the sole.
 3. The sole of claim 2, further comprising a rear portion of the sole, wherein a decrease in the thickness of the sole along the width of the lateral portion in the rear portion of the sole is greater than a decrease in the thickness of the sole along the width of the medial portion in the rear portion of the sole.
 4. The sole of claim 1, wherein a rate of decrease in the thickness of the sole along the width of at least one of the lateral portion and the medial portion progressively varies along a length of the sole, between a front of the central transition zone and a rear of the central transition zone.
 5. The sole of claim 4, wherein the rate of decrease in the thickness of the sole along the width of the lateral portion progressively increases along the length of the sole, from the front of the central transition zone to the rear of the transition zone.
 6. The sole of claim 5, wherein the rate of decrease in the thickness of the sole along the width of the medial portion progressively decreases along the length of the sole, from the front of the central transition zone to the rear of the transition zone.
 7. The sole of claim 4, wherein a thickness measured at a front of the centerline of the central transition zone of the sole is greater than a thickness measured at a rear of the centerline of the central transition zone of the sole.
 8. The sole of claim 7, wherein the thickness of the sole progressively decreases from the front edge portion of the sole to the rear edge portion of the sole.
 9. The sole of claim 1, wherein the central transition zone has a profile chosen from at least one of flat, rounded, pointed or an indented gap.
 10. The sole of claim 1, wherein the central transition zone has a width that ranges from about 0.5 mm to about 20 mm.
 11. The sole of claim 1, wherein the central transition zone extends along approximately 20% to 80% of a length of the sole.
 12. A sole for a shoe having a front, a rear, a striking surface, a medial edge, and a lateral edge, the striking surface of the sole comprising: a central transition zone having a centerline extending substantially from the front of the sole to the rear of the sole, a medial edge, and a lateral edge, the central transition zone dividing the striking surface of the sole into a medial portion and a lateral portion; a front medial section of the striking surface having a width extending from the medial edge of the central transition zone to the medial edge of the sole, a thickness of the sole decreasing along a width of the front medial section from the medial edge of the central transition zone toward the medial edge of the sole such that the front medial section is disposed at a first angle of inclination with respect to a support surface; a front lateral section of the striking surface having a width extending from the lateral edge of the central transition zone to the lateral edge of the sole, a thickness of the sole decreasing along a width of the front lateral section from the lateral edge of the central transition zone toward the lateral edge of the sole such that the front lateral section is disposed at a second angle of inclination with respect to the support surface; a rear medial section of the striking surface having a width extending from the medial edge of the central transition zone to the medial edge of the sole, a thickness of the sole decreasing along a width of the rear medial section from the medial edge of the central transition zone toward the medial edge of the sole such that the rear medial section is disposed at a third angle of inclination with respect to the support surface; and a rear lateral section of the striking surface having a width extending from the lateral edge of the central transition zone to the lateral edge of the sole, a thickness of the sole decreasing along a width of the rear lateral section from the lateral edge of the central transition zone toward the lateral edge of the sole such that the rear lateral section is disposed at a fourth angle of inclination with respect to the support surface; wherein the first angle of inclination is greater than the second angle of inclination.
 13. The sole of claim 12, wherein the fourth angle of inclination is greater than the third angle of inclination.
 14. The sole of claim 13, wherein a thickness measured at a front of the centerline of the central transition zone of the sole is greater than a thickness measured along a rear of the centerline of the central transition zone of the sole.
 15. The sole of claim 14, wherein the thickness of the sole along the centerline of the transition zone progressively decreases from the front of the sole to the rear of the sole.
 16. The sole of claim 12, wherein a decrease in the thickness of the sole along the width of the front lateral section is less than a decrease in the thickness of the sole along the width of the front medial section.
 17. The sole of claim 16, wherein a decrease in thickness of the sole along the width of the rear lateral section is greater than a decrease in the thickness of the sole along the width of the rear medial section.
 18. The sole of claim 12, further comprising a convergence zone defining a transition area between the front lateral and medial sections of the striking surface and the rear lateral and medial sections of the striking surface.
 19. The sole of claim 18, wherein a rate of decrease in the thickness of the sole along the width of the front lateral section progressively increases along the length of the sole, from the front of the central transition zone to the convergence zone.
 20. The sole of claim 19, wherein a rate of decrease in the thickness of the sole along the width of the rear lateral portion progressively increases along the length of the sole, from the convergence zone to the rear of the central transition zone.
 21. The sole of claim 20, wherein a rate of decrease in the thickness of the sole along the width of the front medial section progressively decreases along the length of the sole, from the front of the central transition zone to the convergence zone.
 22. The sole of claim 21, wherein a rate of decrease in the thickness of the sole along the width of the rear medial section progressively decreases along the length of the sole, from the convergence zone to the rear of the central transition zone.
 23. The sole of claim 12, wherein the central transition zone has a profile chosen from at least one of flat, rounded, pointed or an indented gap.
 24. The sole of claim 12, wherein the central transition zone has a width that ranges from about 0.5 mm to about 20 mm.
 25. The sole of claim 12, wherein the central transition zone curves as it extends from the front of the sole to the rear of the sole.
 26. The sole of claim 25, wherein the centerline runs approximately parallel to the medial edge of the sole.
 27. The sole of claim 12, wherein the first angle of inclination ranges from about 0 degrees to about 15 degrees.
 28. The sole of claim 12, wherein the second angle of inclination ranges from about 0 degrees to about 15 degrees.
 29. The sole of claim 12, wherein the third angle of inclination ranges from about 0 degrees to about 15 degrees.
 30. The sole of claim 12, wherein the fourth angle of inclination ranges from about 0 degrees to about 15 degrees.
 31. A method for utilizing a shoe sole to coordinate simultaneous movement of a foot along a sagittal axis, a frontal axis, and a transverse axis, the method comprising: maintaining the foot in a natural supinated position when a striking surface of the sole strikes a surface being traversed; and transitioning the foot over a central transition zone of the sole to roll inwardly into a push-off pronated position.
 32. The method of claim 31, wherein transitioning the foot includes moving the striking surface of the sole from a rear lateral section of the striking surface that forms a lateral angle of inclination with a support surface to a front medial section of the striking surface that forms a medial angle of inclination with the support surface. 